Gymnema sylvestre Leaf Extract: A 52-Week Dietary Toxicity Study in Wistar Rats

Yukio Ogawa, Kiyoshi Sekita, Takashi Umemura, Minoru Saito, Atsushi Ono, Yasushi Kawasaki, Osayuki Uchida, Yuko Matsushima, Tohru Inoue, Jun Kanno

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15 Citations (Scopus)


A 52-week study of oral-repeated-dose toxicity for the extraction powder of Gymnema sylvestre (GS), Indian-native genus, Metaplexis japonica, was conducted in both genders of Wistar rats. The rats were administered a graded dose of GS at 0.01, 0.10 and 1.00% of basal powder diet, along with a group fed solely with the basal powder diet without GS, for 52 weeks. General conditions were recorded daily. Body weights and food consumptions were recorded weekly up to 12 weeks, and thereafter at longer intervals. At 26 weeks, for an intermediate examination, and 52 weeks, for the final examination, animals were subjected to hematology, serum chemistry, and pathological examination. None of the animals died in the period up to 52 weeks. No exposure-related changes in body-weight, in the food consumption, in the hematological examinations, or in the serum biochemical examinations were recognized. No histopathological alterations were seen. Thus, it was concluded that there was no toxic effect in rats treated with GS at up to 1.00% in the diet for 52 weeks. The no-observable-effect level from this study is 1.00% GS, ie., 504 mg/kg/day for male and 563 mg/kg/day for female as mean daily intake, for 52 weeks.

Original languageEnglish
Pages (from-to)8-18
Number of pages11
JournalJournal of the Food Hygienic Society of Japan
Issue number1
Publication statusPublished - 2004
Externally publishedYes


  • 52-week toxicity study
  • Gymnema sylvestre leaf extract
  • Health food

ASJC Scopus subject areas

  • Food Science
  • Public Health, Environmental and Occupational Health


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